body {
  background-color: #f0f0f0;
}
/* less嵌套 */
div {
  color: hsl(290, 86%, 77%);
  font-size: 14px;
}
div p {
  color: blue;
}
div p::after {
  content: "我是p标签的after伪元素";
}
div a {
  color: hsl(290, 86%, 77%);
}
div a:hover {
  color: blue;
}
div {
  width: 100px;
  height: 25px;
  font-size: 8px;
  border: 2px solid red;
  background-color: #444444;
}
